Systemic asphyxia occurs in 20 of 1000 births and can lead to hypoxic ischemic encephalopathy (HIE). Between 10% and 60% of neonates with HIE die or have permanent deficits. Although hypothermia is the standard of care for HIE, we cannot differentiate patients who respond to hypothermia from non-responders. The primary goal of this project is to conduct a proof-of-concept study to validate biomarkers that will rapidl and accurately identify individuals likely to respond to hypothermia or who will die. We will measure two serum biomarker levels obtained during the first 96 hours of life with the goal to stratify neonates with HIE into three groups: 1) responders to hypothermia 2) non-responders at high risk for surviving with neurological and/or developmental deficits and 3) neonates who die. We will also examine relationships between biomarker levels and brain injury assessed by MRI 7-12 days after birth. Based on data using Ubiquitin C-terminal hydrolase L1 (UCH-L1) and glial fibrillary acidic protein (GFAP) as biomarkers of brain injury in several neurological conditions such as TBI and stroke, we will examine the potential of these protein biomarkers to distinguish the three groups. Our central hypothesis is that GFAP and UCH-L1 are elevated in neonates with HIE and that changes in these proteins will predict response to hypothermia and death. We will determine if analysis of these biomarkers can: (1) assist in early and accurate diagnosis of HIE; (2) predict responders vs. non-responders to hypothermia; (3) predict brain damage magnitude as assessed by MRI or death. Specific Aim 1a: Supplement existing serum sample base of 37 patients with additional samples from no less than 3 patients treated with hypothermia. We are currently banking samples from control 40 healthy neonates (n=20) and clinical controls (n=20) from neonates assessed for jaundice. Specific Aim 1b: Complete assay analysis of UCH-L1 and GFAP from all serum samples. Specific Aim 2a: Determine whether pre-treatment concentrations of the biomarkers UCH-L1 and GFAP can predict the response to hypothermia assessed by volumetric MRI 7-12 days after birth or death. We will also determine the temporal changes of biomarkers during the course of hypothermic treatment. Specific Aim 2b: Determine if increased levels of UCH-L1 and GFAP, or their ratios measured within 12 hours of birth, predict death or the volume of brain injury assesses by volumetric MRI 7-12 days following birth. Commercialization potential. Banyan Biomarker's, Inc. (www.banyanbio.com) has completed enrollment for a FDA sanctioned 2000 patient, international Pivotal Trial (ALERT-TBI: www.clinicaltrials.gov) to determine the clinical utility of UCH-L1 and GFAP to supplement acute diagnosis of mild and moderate TBI in adults. A successful completion of this study will extend the applicability of the biomarkers to HIE afflicted neonates.